If you paid in BTC and didn't get the product -- apparently, in this case, it wasn't even shipped -- then you must be refunded fully in BTC.

I can't believe some of the stuff I'm reading here. It's un-fucking-believable. Market changes in BTC are completely irrelevant, unless the 'service' is attempting to con people out of their bitcoins when the market goes up. Yaaaay, free bitcoins for doing nothing! Ridiculous.